1. Field of the Invention
The present invention is related to a combination weighing apparatus for weighing articles supplied to a plurality of weighing hoppers, respectively, combining the weights of the articles thus supplied to thereby obtain a combination in which the combined weights fall within a predetermined combination tolerance, discharging and collecting the articles from the hoppers in the combination, thereby obtaining articles of a predetermined weight.
2. Description of the Prior Art
As an apparatus for weighing cooked foods, cooked beans, foods boiled down in soy or other sticky articles (to be referred to as xe2x80x9carticlesxe2x80x9d hereinafter) by a predetermined weight, there is known a semiautomatic combination weighing apparatus 1 as shown in FIGS. 14 and 15. This apparatus comprises an upper-stage table 2, a plurality of lower-stage supply feeders 3 into which articles are supplied from a plurality of outlets of the table 2, a plurality of pool hoppers 4 provided below the tip ends of the supply feeders 3 and temporarily storing the articles supplied from the supply feeders 3, respectively, a plurality of weighing hoppers 5 provided below the pool hoppers 4 and receiving and weighing the articles discharged from the pool hoppers 4, respectively, a plurality of booster hoppers 6 provided below the weighing hoppers 5 and temporarily storing the articles discharged from the weighing hoppers 5 to allow them to be combined, respectively, and a lowest-stage conveyor 7 collecting the articles discharged from these booster hoppers 6 in one portion.
In the semiautomatic weighing apparatus of this type, many articles are stocked on the table 2. An operator or operators need to input the articles into the outlets of the table 2 which outlets are connected to the respective supply feeders 3, while supplying the articles. Due to this, if the number of operators is one, a compact size apparatus having five groups of vertically three stages of hoppers arranged in horizontal rows is employed as shown in FIG. 14. If the number of operators is two, a high speed, high precision apparatus having ten groups of vertically three stages of hoppers arranged in horizontal rows is employed as shown in FIG. 15 (U.S. Pat. No. 5,767,453).
Meanwhile, the weighing apparatus for one operator is inferior to the weighing apparatus for two operators in capability and precision. Namely, as for capability, the maximum weighing processing capability of the weighing apparatus for one operator is 25 times/minute, whereas that of the weighing apparatus for two operators is 60 times/minute. As for precision which varies according to the features of articles, operating conditions and the like, the former apparatus has error of about 2 g to 6 g for a target weight value 100 g, whereas the latter apparatus has error of about 1 to 2 g.
Generally, it is convenient for a user involved in producing various types of articles in small quantity to purchase a plurality of weighing apparatuses for one operator. However, if the plural apparatuses for one operator are used in busy to weigh articles of the same type, the advantages of high speed and high precision as seen in the apparatus for two operators cannot be disadvantageously obtained.
The present invention has been made in view of the above-stated problems. It is, therefore, an object of the present invention to provide a weighing apparatus suited for weighing purposes by electrically coupling a plurality of apparatuses for one operator which can be used individually to provide a new combination weighing apparatus which can be used as an apparatus for a plurality of operators.
A combination weighing apparatus according to the present invention comprises a plurality of hoppers arranged in horizontal rows, a conveyor provided below the plurality of hoppers for transporting articles discharged from the plurality of hoppers, respectively, to a predetermined collection position, and a controller for controlling a combination weighing operation for selecting a combination of hoppers so that a combination weight value obtained by combining some of weight values of the articles supplied to the plurality of hoppers falls within a predetermined combination tolerance, and discharging the articles from the hoppers in the selected combination. This combination weighing apparatus is featured in that when a plurality of the combination weighing apparatuses are provided and discharge ends of the conveyors of the respective combination weighing apparatuses are disposed to discharge the articles at the same collection position, the controller is adapted to cooperate with the controller of the other combination weighing apparatuses so that the plurality of combination weighing apparatuses conduct the combination weighing operation with weight values obtained in all the combination weighing apparatuses.
Thus, normally, a plurality of apparatuses can be used separately. When busy, these plural apparatuses can be coupled to one another to be used for a plurality of operators. It is, therefore, possible to conduct weighing operation according to weighing purposes intended to provide high precision and high capability.
In a preferred embodiment of the present invention, the conveyor is constructed to be able to select a transport direction between a forward transport direction and a backward transport direction.
Thus, it is possible to provide variety of layouts for physically coupling and separating the plurality of apparatuses.
In a preferred embodiment of the present invention, a return regulating member for detaching the articles from the conveyor at the collection position, is provided to be associated with the conveyor.
In a preferred embodiment of the present invention, the apparatus is adapted to be disposed together with the other apparatus in a side-by-side fashion.
In a preferred embodiment of the present invention, the apparatus is adapted to be disposed together with the other apparatus to confront each other.